Breast cancer is the most common cancer for women in both the developed and less developed world. Despite considerable medical advances, more than 40 000 women have died in the US in 2015 and over half a million worldwide.

When a woman is diagnosed with breast cancer, it is generally classified as one of a number of subtypes. The latest research presented at the European Breast Cancer Conference in Amsterdam is giving hope to the patients that have been diagnosed positive with HER2 breast cancer, the type of breast cancer where the cancer cells have large amounts of a molecule called HER2 on their surface.

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Mammograms showing a normal breast (left) and a breast with cancer (right, white arrows). By Bakerstmd (Own work) [CC BY-SA 4.0], via Wikimedia Commons

The trial included 257 women who had been diagnosed with HER2 positive breast cancer and were waiting to have surgery. Remarkably, in 66 of 127 women that have received a combination of two drugs Herceptin and Lapatinib, the tumor has disappeared completely and in another 11, the tumor has shrunken significantly in only 11 days. Usually the two drugs are commonly used during one type of breast cancer treatment, following tumor-removal surgery and conventional chemotherapy.

It’s important to remember that while this generally suggests a treatment has worked well, it also means there are still cancer cells remaining from which the disease could grow back. This is especially important because HER2 positive breast cancer is more likely to come back after treatment than some other types of breast cancer. But nevertheless, these are exciting results, particularly when you consider that women with Stage 2 cancer were also among those who responded to the combination therapy.

It’s also important to remember that the researchers didn’t see any response in the other 48 women who received the drug combination which indicates that there must be something different about some HER2 positive tumours that makes them exquisitely sensitive to the drug combination.

As explained by the Cancer Research UK, the next steps should answer the following questions.

First, researchers and doctors have to come up with a way of identifying those women who are more sensitive to pre-surgery treatment. Following this, they will need to run clinical trials to see if these women really can avoid chemotherapy treatment and if the current standard of care for some HER2 positive breast cancer patients can and should be changed.

 

Jana Erjavec, PhD, BioSistemika LLC

Also featured in: IFL Science, BBC News, Cancer research UK

Featured image: Breast cancer cell, by Unknown photographer [Public domain], via Wikimedia Commons